1. Technical Field
The present disclosure relates to the field of device to device (D2D) COMMUNICATION, AND IN PARTICULAR, TO D2D COMMUNICATION METHODS AND D2D-enabled wireless devices
2. Description of the Related Art
Device-to-device (D2D) communication is direct communication between devices and is a new topic in 3GPP (3rd Generation Partnership Project) LTE (Long Term Evolution) Release 12. D2D communication could happen with wireless network coverage (e.g. for commercial case) or without network coverage (e.g. for public safety). FIG. 1 illustrates exemplary D2D communications with and without wireless network coverage. On the left side of FIG. 1, UE 101 and UE 102 are within the wireless network coverage of eNB 103, but they are communicating with each other directly (i.e. not through eNB 103) and eNB 103 is used for synchronization, resource scheduling or the like. On the right side of FIG. 1, UE 104 and UE 105 are not within any wireless network coverage, and they are communicating with each other directly.
3GPP RAN1#76 meeting agreed eNB scheduling based resource allocation (Mode 1) as baseline resource allocation method in network-coverage (INC) scenario and UE selection on its own based resource allocation (Mode 2) is baseline resource allocation method in out-of-coverage (OOC) scenario.